Not applicable. cl STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable.
Not applicable.
This invention relates to a finger-operable pump for dispensing a product from a container. The invention is more particularly related to an actuator or button at the top of the pump that is depressed by the finger of the user so that the pump discharges the product through the actuator.
A variety of packages that include a finger-operable dispensing pump on a container have been developed for household products, personal care products, and other products. It would be desirable to provide an improved pump actuator or button for use with such packages.
The actuator is typically designed to be depressed by the user pushing a finger down on a portion of a top surface of the actuator. See, for example, the actuator design disclosed in the U.S. Pat. No. 4,986,453. While such an actuator functions exceptionally well in the applications for which it is intended, it would be desirable to provide an improved actuator which has a means for delineating the region on the actuator which is to be pushed down by the user""s finger.
Additionally, it would be advantageous if such an improved actuator could incorporate a finger pad against which the end of the user""s finger could be pressed for forcing the actuator downwardly. In some applications, it may be desirable to provide such a finger pad made of material that is softer than the rest of the actuator, or which otherwise feels different and provides a different tactile sensation than the rest of the actuator.
Further, it would be desirable in some applications to provide an actuator with a finger pad that includes a color, texture, or material that is different from the color, texture, or material in the rest of the actuator. Preferably, such a finger pad could provide improved frictional engagement with a finger under wet conditions so as to minimize the tendency of the finger to slip off of the actuator.
Such an improved actuator should be susceptible of accommodating a variety of aesthetically pleasing designs adaptable for use on various dispensing pumps.
It would also be beneficial if such an improved dispensing pump actuator could readily accommodate its manufacture from a variety of different materials.
Further, it would be desirable if such an improved actuator could be provided with a design that would accommodate efficient, high quality, large volume manufacturing techniques with a reduced product reject rate.
Preferably, the improved actuator should also accommodate high speed manufacturing techniques that produce actuators having consistent structural and functional characteristics unit-to-unit with high reliability.
The present invention provides an improved dispensing pump actuator which can accommodate designs having the above-discussed benefits and features.
The present invention provides an improved actuator for a finger-operable pump wherein the actuator is adapted to be disposed on the distal end of a pump discharge tube or stem. The improved actuator can be readily designed to provide an improved top surface (against which the user""s finger presses to actuate the pump) which is softer than the rest of the actuator and which may provide increased friction to prevent slippage between the user""s finger and the actuator. The top of the actuator can also be readily provided with a different color, as well as a different texture or material, than the rest of the actuator.
According to one aspect of the invention, the actuator includes a body for being mounted to the discharge tube. The actuator body comprises a first, generally rigid piece which is molded from a material and which defines an outwardly facing, force-receiving region. The actuator includes a second piece which is molded from a material (preferably a material that is different from the first material) onto the first, rigid piece force-receiving region and bonded to the first, rigid piece to define a finger pad against which a finger may be pressed to depress the actuator on the pump.
In a preferred embodiment, the first, rigid piece or body is molded from a thermoplastic material, such as polypropylene, and the second piece is molded from a rubber-based, thermoplastic elastomer which will feel softer compared to the polypropylene first piece or body. The finger pad may advantageously have a different color from the polypropylene first piece or body.
Further, it is presently contemplated that a preferred form of making the actuator includes bi-injection molding techniques, although other molding techniques could be employed, such as two-shot molding, multi-injection molding, or over-molding. In general, the actuator body is preferably made by injecting a first material, such as polypropylene, into the vacant cavity of an injection molding tool. During the first injection, part of the cavity is blocked to prevent the melt (e.g., the hot, flowable polypropylene) from filling a certain region of the cavity. The first material is then allowed to cool briefly. Subsequently, the blocking component or components are moved, or removed from the molding tool, to expose the additional region of the cavity volume. A second injection of material is then effected, typically with a material that is different from the first material. The second injection of the material fills the remaining, vacant region of the cavity and bonds to the substrate material of the first injection.
Numerous other advantages and features of the present invention will become readily apparent from the following detailed description of the invention, from the claims, and from the accompanying drawings.